Field of Disclosure
The present disclosure relates to a packaging structure. More particularly, the present disclosure relates to a packaging structure of an organic optoelectronic device.
Description of Related Art
As organic optoelectronic devices are developed rapidly in recent years, their corresponding performance and process are improved significantly, and their applications become broader and broader. The organic optoelectronic devices mainly include an organic solar cell (Organic Photovoltaic; OPV) and an organic light emitting diode display (OLED). After having breakthrough performance, the organic optoelectronic devices face commercialization challenges to be overcome. One of the most critical problems for commercialization of the organic optoelectronics is how to prolong component life. Most of the materials used in the organic optoelectronic devices are highly unstable, and will be deteriorated rapidly when contacting moisture and oxygen in the atmosphere. The reason for such deterioration is that most of the organic optoelectronic materials have the conjugated structures of low energy band gaps, and thus the materials are easily excited by irradiation or heat to generate oxidation reaction with oxygen and water molecules in the environment. Meanwhile, the low energy band gap organic optoelectronic materials usually have relatively high occupied molecular orbital, and may easily have oxidation reaction with oxygen even if being at an un-excited ground state, and thus losing the optoelectronic features. In addition to the instability, the organic optoelectronic devices mostly use low work function metals as the electrodes, such as calcium, barium, magnesium, etc. The low work function metals all have strong reducibility and will have severe oxidation reaction even with a tiny amount of water or oxygen, thus deteriorating the devices rapidly. Therefore, a packaging technique is needed for blocking the organic optoelectronic devices from water and oxygen, prolonging the operation life of the organic optoelectronic devices.